Retrograde Delivery of Resurfacing Devices

ABSTRACT

A method according to one embodiment may provide access to an articular surface of a bone. The method includes forming a passage through at least a portion of the bone. The passage provides an opening in the articular surface. The method further includes inserting a tether through the passage. The tether inserted through the passage can be coupled to at least one device from an insertion site remote from the articular surface. The tether can be withdrawn through the passage to convey the device to a location proximate the articular surface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/994,453 (now U.S. Pat. No. 7,896,885), filed Nov. 22, 2004, whichclaims the benefit of U.S. provisional patent application Ser. No.60/523,810, filed on Nov. 20, 2003, and is a continuation-in-part ofU.S. patent application Ser. No. 10/308,718, (now U.S. Pat. No.7,163,541), the entire disclosures of which are incorporated herein byreference.

FIELD

The present disclosure is directed at a system and method of repairing adefect in an articular joint surface.

BACKGROUND

Articular cartilage, found at the ends of articulating bone in the body,is typically composed of hyaline cartilage, which has many uniqueproperties that allow it to function effectively as a smooth andlubricious load bearing surface. Hyaline cartilage problems,particularly in knee, hip joints, and should joints, are generallycaused by disease such as occurs with rheumatoid arthritis or wear andtear (osteoarthritis), or secondary to an injury, either acute (sudden),or recurrent and chronic (ongoing). Such cartilage disease ordeterioration can compromise the articular surface causing pain andeventually, loss of joint movement. As a result, various methods havebeen developed to treat and repair damaged or destroyed articularcartilage.

For smaller defects, traditional options for this type of probleminclude leaving the lesions or injury alone and living with it, orperforming a procedure called abrasion arthroplasty or abrasionchondralplasty. The principle behind this procedure is to attempt tostimulate natural healing. The bone surface is drilled using a highspeed rotary burr or shaving device and the surgeon removes about 1 mmof bone from the surface of the lesion. This creates an exposedsubchondral bone bed that will bleed and will initiate a fibrocartilagehealing response. One problem with this procedure is that the exposedbone is not as smooth as it originally was following the drilling andburring which tends to leave a series of ridges and valleys, affectingthe durability of the fibrocartilage response. Further, although thisprocedure can provide good short term results, (1-3 years),fibrocartilage is seldom able to support long-term weight bearing and isprone to wear, soften and deteriorate.

Another procedure, called Microfracture incorporates some of theprinciples of drilling, abrasion and chondralplasty. During theprocedure, the calcified cartilage layer of the chondral defect isremoved. Several pathways or “microfractures” are created to thesubchondral bleeding bone bed by impacting a metal pick or surgical awlat a minimum number of locations within the lesion. By establishingbleeding in the lesion and by creating a pathway to the subchondralbone, a fibrocartilage healing response is initiated, forming areplacement surface. Results for this technique may be expected to besimilar to abrasion chondralplasty.

Another means used to treat damaged articular cartilage is a cartilagetransplant. Essentially, this procedure involves moving cartilage froman outside source or other knee or from within the same knee into thedefect. Typically, this is done by transferring a peg of cartilage withunderlying bone and fixing it in place with a screw or pin or by a pressfit. Although useful for smaller defects, large defects present aproblem, as this procedure requires donor pegs proportionate to therecipient bed. Large diameter lesions may exceed the capacity to borrowfrom within the same knee joint and rule out borrowing from anothersource.

Larger defects, however, generally require a more aggressiveintervention. Typically treatment requires replacing a portion or all ofthe articular surface with an implant or prosthetic having an outerlayer that that is polished or composed of a material that provides alubricious load bearing surface in approximation of an undamagedcartilage surface. Replacement of a portion, or all, of the articularsurface requires first cutting, boring, or reaming the damaged area toremove the damaged cartilage. A recess to receive an implant orprosthetic is formed at the damaged site. The implant or prosthetic isthen secured to the bone in an appropriate position in the recess.

The treatment and/or replacement procedure often requires direct accessto the damaged surface of the cartilage. While the most commonly damagedportions of some joints may easily be accessed for repair using aminimally invasive procedure some joints are not nearly as accessible.For example, the superior or medial femoral head, the medial humeralhead, the glenoid, etc. do not permit direct access sufficient to carryout replacement of the articular surface in a minimally invasive manner.In fact, repair of such obstructed joints often requires an invasiveprocedure and necessitates complete dislocation of the joint. Proceduresof such an invasive nature may be painful and require an extendedrecovery period.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the claimed subject matter will be apparentfrom the following detailed description of exemplary embodimentsconsistent therewith, which description should be considered inconjunction with the accompanying drawings, wherein:

FIG. 1 depicts a femoral head having a target site for receiving aprosthetic implant;

FIG. 2 illustrated the formal head of FIG. 1 having a passage drilledthere-through consistent with the present disclosure;

FIG. 3 shows the use of a wire inserted through the femoral headshuttling devices to the target area; and

FIG. 4 depicts a reamer employed via a drive shaft extending through thepassage in the femoral head;

FIG. 5A is a sectional view of an exemplary fixation screw consistentwith one embodiment of the present disclosure; and

FIG. 5B is a side partial cross-sectional view of the exemplary fixationscrew of FIG. 5A, implanted in the defect, with suture strands placedtherethrough, in a surgical procedure consistent with one embodiment ofthe present disclosure.

DETAILED DESCRIPTION

As a general overview, the present disclosure may provide a system andmethod for replacing at least a portion of an articular surface of ajoint. The present disclosure may allow instruments and/or other devicesto be delivered to a target area, e.g. an articular surface or portionthereof, within a joint. According to one aspect, the present disclosuremay allow instruments and/or other devices to be delivered to a targetarea that is obscured from direct frontal or axial access. Furthermore,consistent with the system and method herein, the instruments and/ordevices delivered to the target area may be used to perform a diagnosticand/or therapeutic procedure on a target area obscured from directfrontal or axial access. According to one embodiment, a method isprovided for repairing a defect in an articular surface of a joint. Themethod herein may be useful, for example, for repairing defects onportions of an articular surface of a joint that are obstructed fromdirect access by mating joint surfaces and/or other anatomical features.Such obstructed articular surfaces may be accessed and/or repairedwithout requiring complete dislocation of the joint. Accordingly, thepresent disclosure may provide a less invasive system and method forrepairing an articular joint surface.

Embodiments of the present disclosure are described in the context ofrepairing a region of the articular surface of a femoral head.Specifically, the illustrated and described embodiment is directed atthe retrograde access, implant site preparation, and delivery of aprosthetic resurfacing device to the femoral head. Those having skill inthe art will appreciate, however, that the principles herein may beutilized for accessing target areas other than the femoral head and maybe used in connection with procedures other than prosthetic resurfacingof an articular surface. Without intending to limit the claimed subject,in addition to providing retrograde delivery of implants, diagnosticdevices, surgical instruments, etc., to the superior or medial femoralhead, the method herein is equally suitable for retrograde delivery tosites such as, cut not limited to, the medial humeral head, tibialsurface and patella. Similarly, the method herein may be used forthru-bone delivery of prosthetic implants, diagnostic devices, surgicalinstruments devices, etc. to sites such as the glenoid, acetabulum,trochlear groove, etc.

Referring to FIG. 1, the system is depicted with reference to a femoralhead 10. A region of the articular surface of the femoral head 10 to bereplaced, i.e., the target area 12, is indicated by broken lines.According to one embodiment, a method herein may include drilling apassage along a predetermined working axis 13 through the femur 11towards the target area 12 on the femoral head 10. The passage throughthe femur 11 may provide access to the target area 12 of the femoralhead 10. In the case of the illustrated embodiment, the origin of thedrill site may be on the body of neck of the femur 11 directed towardthe target area 12 on the femoral head 10.

The passage through the femur 11 may be oriented generally normal to thearticular surface of the femoral head 10 in the vicinity of the targetarea 12. As shown in FIG. 1, a drill guide 14 may be used to orient anaccess passage generally normal to the target area 12 of the articularsurface of the femoral head 10. The drill guide 14 may include alocating ring 16 and a drill bushing 18. The drill bushing 18 may beconnected to the locating ring 16 by an arm 15 of the drill guide 14.The arm 15 of the drill guide 14 may orient the drill bushing 18 in agenerally coaxial relationship relative to the locating ring 16 alongthe working axis 13. As depicted, the locating ring 16 may include agenerally annular member. As such, when the locating ring 16 is disposedon the arcuate surface of the femoral head 10, the locating ring 16 mayattain an orientation generally normal to the surface of the femoralhead 10. The coaxial orientation of the drill bushing 18 and thelocating ring 16 may allow a passage to be drilled through the femoralhead 10, and guided by the drill bushing 18, to be substantially normalto the articular surface of the femoral head 10 at the target area 12.Consistent with the present disclosure, a drill axis defined by thedrill bushing 18 may have an orientation that is not normal to thefemoral head 10 in the target area 12.

Turning to FIG. 2, a passage 20 is shown provided through the femur 11,extending trough the femoral head 10 in the region of the target area12. As discussed above, the passage 20 may be formed by drilling throughthe femur 11 using a drill bit guided by the drill bushing 18 of thedrill guide 14. A tether 22, such as a wire, suture, thread, etc., maybe inserted through the passage 20 so that the tether 22 may extend fromthe femoral head 10. The tether 22 may be advanced though the passage 20with the aid of a guide pin 24. For example, the guide pin 24 may be acannulated rod and the tether 22 may be at least partially disposed in alumen of the guide pin 24. According to an alternative embodiment, theguide pin 24 may simply be a rod that may be used to push, or otherwiseadvance, the tether 22 through the passage 20. As shown, the tether 22may include a loop 26 on the distal end thereof. The loop 26 or featuremay be used for attaching instruments, devices, etc., to the tether 22.Accordingly, various attachment features other than a loop may suitablybe employed herein.

The tether 22 may be used to ferry, shuttle, or otherwise convey variousdiagnostic devices, surgical instruments, prosthetic devices, etc. froma remote insertion site, e.g., exterior to the joint, to the target area12. In one embodiment, the tether 22 may be used to convey instruments,devices, etc., to the target area 12 without requiring direct and/oraxial access to the target area 12. For example, referring the FIG. 3,the tether 22 may be coupled to a reamer 28 outside of the joint. Thereamer 28 may include a body 31 and one or more cutting features 29 andmay be used for excising a portion of the femoral head 10 in the regionof the target area 12. The tether 22 may be advanced or pulled throughthe femur 11 and out from the joint area to allow the reamer 28 to beattached to the tether 22 at the remote insertion site. Advancing thetether 22 from femoral head 10 may include pulling the distal end of thetether 22 completely from the body of a patient, e.g., in an embodimentin which the remote insertion site it outside of the patient. The loop26 at the distal end of the tether 22 may be coupled to a cooperatingfeature 30 on an underside of the reamer 28. The reamer 28 may beconveyed to the target area 12 by withdrawing the tether 22 back throughthe passage 20, thereby pulling and or guiding the reamer 28 to thetarget area 12. Withdrawing the tether 22 back through the passage 20may transport the reamer 28 to the target area 12 and/or may generallycenter the attachment feature 30 of the reamer 28 relative to thepassage 20.

Turning to FIG. 4, once the reamer 28 has been transported to the targetarea 12, the reamer 28 may be coupled to a drive shaft 32 disposedextending at least partially through the passage 20. In one embodiment,the drive shaft 32 may be a cannulated shaft that may be threaded overthe tether 22. The reamer 28 and the drive shaft 32 may includecooperating features allowing the driveshaft 32 to transmit torque tothe reamer 28. The cooperating features of the drive shaft 32 and thereamer 28 may include torque transmitting features such as cooperating acooperating socket and plug, e.g., a mating hex shaft and hex socket.Consistent this variety of torque transmitting coupling the wire 22 maybe used to pull the reamer 28 towards in the drive shaft 32 in order tomaintain the connection between the cooperating features of the driveshaft 32 and the reamer 28. Alternatively, the cooperating features ofthe drive shaft 32 and the reamer may be releasably securable to oneanother. According to one such embodiment, the cooperating features ofthe drive shaft 32 and the reamer 28 may include cooperating threadedcomponents that screw together, cooperating snap-fit features, etc.

At least a portion of the femoral head 10 in the general region of thetarget area 12 may be excised by rotatably driving the reamer 28 andpulling the reamer 28 into the femoral head 10. The reamer 28 may berotatably driven manually and/or using a drive motor, for example usinga drill. The reamer 28 may be pulled into the femoral head 10 bywithdrawing the drive shaft 32, in an embodiment in which the driveshaft 32 and the reamer 28 are releasably secured to one another.Additionally, and/or alternatively, the reamer 28 may be pulled into thefemoral head by withdrawing or pulling on the tether 22, which may, insome embodiments, remain coupled to the reamer 28 during the excisionoperation.

In addition to conveying the reamer 28 to the target area 12, the tether22 may also be used to transport various other devices and/orinstruments to the target area 12. Devices and/or instrumentstransported to the target area 12 by the tether 22 may also be centeredabout the passage 20 through the femur 11 similar to the reamer 28. Forexample, in an embodiment consistent with the present disclosure, alsoin the general context of an articular surface repair procedure, thetether 22 may be used to shuttle or transport an anchoring device, suchas a screw 33, FIGS. 5A and 5B, to the target area 12. The screw 33 maybe provided having an internal driving feature 34, e.g., a hex socketfeature, a Torx™ socket, etc. The tether 22 may be threaded through acannulated driver 35 which may be inserted through the passage 20. Thetether 22 may be used to convey the screw 33 to the target area 12 andcenter the screw 33 relative to the passage 20. The driver 35 may beengaged with the driving feature 34 of the screw 33 and a holding forcemay be applied to the screw via the tether 22, thereby maintaining theengagement between the driver 34 and the screw 33. With the driver 34and the screw 33 maintained in engagement with one another, the screw 33may be threadably driven into the passage 20 at the target area 12.

In a related manner, the tether 22, alone and/or in conjunction withvarious suitably configured shafts and/or driving elements extendingthrough the passage 20, may be used to transport and operate or installother instruments and devices. Ultimately, the tether 22 may be used toshuttle a prosthetic implant to the target area 12 and install theimplant into an implant site, such as may be created using the reamer28.

Consistent with the foregoing disclosure, a system and method may beprovided for replacing at least a portion of an articular surface of ajoint that is obscured from axial approach. According to one aspect, amethod herein may permit the retrograde delivery of instruments anddevices from an insertion site to a target area on the articularsurface. According to an embodiment, the method may include drilling apassage from an accessible region of a bone removed from a targetarticular surface. The passage may extend toward the target articularsurface. A tether, such as a wire, may be introduced through thepassage, and positioned having a distal end extending from a distalopening of the passage at the target articular surface. The distal endof the tether may be coupled to a prosthetic device, a surgicalinstrument, diagnostic device, etc. The tether may then be drawn backtoward the articular surface, thereby transporting/carrying theprosthetic device, surgical instrument, diagnostic device, etc. to thearticular surface.

According to another aspect, after the a prosthetic device, surgicalinstrument, diagnostic device, etc., has been transported to thearticular surface, the prosthetic device, surgical instrument,diagnostic device, etc. may be engaged by a shaft or pin extendingthrough said passage to said articular surface. The shaft or pin may beused for applying a rotational and/or axial force to the prostheticdevice, surgical instrument, diagnostic device, etc. Using thismethodology, a procedure may be performed on a target are without directaxial or frontal access to the target area.

Those having skill in the art will appreciate that the method herein maybe used for transporting numerous additional instruments, devices, etc.to a working surface having impeded direct axis. Further is should beunderstood that a variety of pins, shafts, catheters, etc. may beinserted through the passage for acting on, interacting with, orco-acting with instruments and/or devices transported to a target areaconsistent with above aspects of the disclosure. Finally, it should alsobe understood that the embodiments disclosed herein are susceptible foruse in procedures in addition to the repair of articular cartilage at ajoint. Accordingly, it should be understood that the embodiments thathave been described herein are but some of the several contemplatedwithin the scope of the claimed subject matter, and are set forth hereby way of illustration, but not of limitation. It is obvious that manyother embodiments, which will be readily apparent to those skilled inthe art may be made without departing materially from the spirit andscope of the claimed subject matter.

1. A method for accessing an articular surface of a bone comprising:forming a passage through at least a portion of said bone, said passageproviding an opening in said articular surface; inserting a tetherthrough said passage; and conveying at least one device from aninsertion site remote from said articular surface to a locationproximate said articular surface.
 2. The method according to claim 1wherein forming said passage comprises positioning a locating ring of adrill guide on said articular surface and drilling a hole through saidbone, said hole guided by a drill bushing of said drill guide.
 3. Themethod according to claim 1, wherein conveying at least one devicecomprises coupling a distal end of said tether to a cooperating featureon said device and withdrawing said tether through said passage.
 4. Themethod according to claim 3 wherein said distal end of said tethercomprises a loop.
 5. The method according to claim 1, wherein saiddevice comprises a reamer, said method further comprising disposing adrive shaft extending at least partially through said passage andcoupling said drive shaft to said reamer.
 6. A method for creating animplant site on an articular surface of a bone comprising: drilling apassage through said bone, wherein a longitudinal axis of said passageextends substantially normal to said articular surface; advancing acannulated drive shaft at least partially within said passage; advancinga shuttle within a lumen of said cannulated shaft while said cannulatedshaft is at least partially disposed within said passage in said bone;conveying a reamer to said articular surface using said shuttle;excising an implant site in a portion of said articular about saiddefect using said reamer; conveying a screw to said implant site usingsaid shuttle; and threadably driving said screw into said passage.
 7. Amethod for creating an implant site on an articular surface of a bonecomprising: locating an annular locating ring of a drill guide generallynormal to said articular surface and at least partially about a defecton said articular surface, said annular locating ring being aligned witha drill bushing to define a working axis extending therethrough;advancing a drill bit at least partially through a drill bushing of saiddrill guide along a working axis to drill a passage through said bonesubstantially normal to said articular surface and provide an opening onsaid articular surface about said defect, said working axis extendingthrough said drill guide and said annular locating ring; advancing acannulated drive shaft at least partially within said passage; advancinga shuttle within a lumen of said cannulated shaft while said cannulatedshaft is at least partially disposed within said passage in said bone,said shuttle further configured to be coupled to a device and to deliversaid device to said working axis; conveying a reamer to said articularsurface using said shuttle; coupling said cannulated drive shaft to saidreamer to excise an implant site in a portion of said articular surfaceabout said defect; conveying a screw to said implant site using saidshuttle; and threadably driving said screw into said passage.
 8. Themethod according to claim 7, wherein said drill guide further comprisesan arm configured to orient said locating ring and said drill bushing ina coaxial relationship.
 9. The method according to claim 7, wherein adistal end of said shuttle comprises an attachment mechanism configuredto be coupled to said device for conveying said device to said articularsurface.
 10. The method according to claim 7, where said reamer isconfigured to be conveyed to said articular surface by coupling saidreamer to said shuttle and withdrawing said shuttle through said passagedrilled through said bone.
 11. The method according to claim 8, whereinsaid arm is configured to orientate said locating ring generally at anangle other than normal to said articular surface.
 12. The methodaccording to claim 7, wherein said shuttle comprises a tether.
 13. Themethod according to claim 12, further comprising advancing a guide pinat least partially within said passage.
 14. The method according toclaim 13, wherein said guide pin comprises a rod.
 15. The methodaccording to claim 14, wherein said guide pin comprises a cannulatedrod.
 16. The method according to claim 15, wherein said tether isconfigured to be at least partially disposed in a lumen of said guidepin.
 17. The method according to claim 7, wherein said drive shaft andsaid reamer each comprise a cooperating threaded component.
 18. Themethod according to claim 7, wherein said drive shaft and said reamereach comprise a cooperating torque transmitting feature.
 19. The methodaccording to claim 18, wherein said cooperating torque transmittingfeatures comprise a cooperating socket and plug.
 20. The methodaccording to claim 12, wherein said attachment mechanism comprises aloop.